One of the most common questions we hear from manufacturers evaluating machine monitoring is connectivity: "How does the data get from my machine to the cloud?" The two main options are WiFi (using your existing factory network) or cellular (a dedicated SIM card that connects independently). Both work, but they have very different tradeoffs — and in most manufacturing environments, cellular is the better starting point.
The Case for WiFi
Leveraging Existing Infrastructure
WiFi has an obvious appeal: you probably already have it. Modern industrial WiFi (802.11ax/Wi-Fi 6) has solid range, reasonable latency, and your IT team understands how to manage it. If your factory network is well-designed, your machines are already within range of access points, and you have IT support to add devices to the network, WiFi can absolutely work for machine monitoring.
Low Bandwidth Requirements
The monitoring data you're sending is also not demanding: telemetry from a machine monitoring system is typically just a few kilobytes per second — nothing that strains a WiFi network. If the infrastructure is already there and IT is supportive, there's no strong technical reason to go cellular instead.
The Case for Cellular
The Factory WiFi Problem
Here's the reality in most manufacturing plants: the factory WiFi was designed for office devices, not industrial IoT. Coverage is patchy near heavy machinery. The shop floor may be a Faraday cage that kills WiFi signals — metal enclosures, CNC machines with steel frames, and high-powered electrical equipment all interfere. And the most important machines are often in the least convenient locations for access points.
More fundamentally, connecting a new device to your factory network means involving IT. That means a ticket, a review process, firewall rule changes, possibly a security audit. For a 10-person job shop, that delay can stretch weeks. Even in larger plants with more IT capacity, there's often a justified reluctance to put unknown IoT devices on the same network as production control systems.
How Cellular Bypasses IT Friction
Cellular bypasses all of this. HLink connects to AWS IoT Core over Soracom's private cellular network — a dedicated IoT APN that's isolated from the public internet. No factory WiFi required, no IT ticket needed, no network credentials to manage. The device arrives, you power it on, and it connects. This is especially important in environments where OT (operational technology) and IT are deliberately separated for security reasons.
Latency and Reliability
For machine monitoring use cases, neither WiFi nor cellular has a latency advantage that matters. You're typically sampling sensor data every 1–5 seconds and tolerating a few seconds of transmission delay — far below the threshold where latency affects your ability to detect and respond to equipment anomalies.
Reliability is where cellular often wins in manufacturing environments. Industrial WiFi suffers from interference, coverage dead zones, and congestion when many devices compete for bandwidth. Cellular networks — especially dedicated IoT networks using Cat-M1 or NB-IoT — are engineered for reliability in challenging RF environments, often with better indoor penetration than conventional WiFi.
Security Considerations
WiFi Network Risks
Both options can be made secure, but they present different risk profiles. Factory WiFi that connects monitoring devices to the same network as PLCs and HMIs creates lateral movement risk — if an IoT device is compromised, an attacker might reach production control systems. Proper VLAN segmentation mitigates this, but it requires deliberate network architecture.
Cellular's Security Advantage
Cellular with a private APN essentially creates a one-way pipe to the cloud: data flows out to your monitoring platform, and nothing flows in. There's no inbound attack surface, no credentials on the device that could be exfiltrated, and no path from the cellular network back to your factory control network. For manufacturers in regulated industries or defense supply chains, this isolation is a meaningful security advantage.
Our Recommendation
Start with cellular. It removes all the integration friction, gets you to live data faster, and keeps your OT network untouched. Once you've validated the business value — once you have 90 days of OEE data and a few prevented failures to point to — you'll have the organizational support to have a deliberate conversation with IT about whether a WiFi integration makes sense for Phase 2.
The best machine monitoring program is the one that actually gets deployed. Cellular gets you there in hours, not weeks.